Dusky Gregory, Stegastes nigricans (Lacépède 1802)

Other Names: Dusky Damselfish, Dusky Farmerfish, Mamo

A Dusky Gregory, Stegastes nigricans, on the Great Barrier Reef, Queensland. Source: Andrew J. Green / Reef life Survey. License: CC by Attribution

A brown damselfish with a darker patch on the body at the rear of the dorsal fin and often lavender markings on the head. Courting males usually have a broad white band across the body and a whitish stripe from the snout to the pectoral-fin base. Juveniles are yellowish to orange-brown with a brown area from the upper head to the blackish spinous dorsal fin.

Video showing male courtship coloration at Rarotonga, in the Cook Islands.

Cite this page as:
Bray, D.J. 2018, Stegastes nigricans in Fishes of Australia, accessed 02 Mar 2024, https://fishesofaustralia.net.au/home/species/385

Dusky Gregory, Stegastes nigricans (Lacépède 1802)

More Info


Houtman Abrohlos to Rowley Shoals and Scott Reef, Western Australia, Ashmore Reef, Timor Sea, and the northern Great Barrier Reef and reefs in the Coral Sea to at least One Tree Island, Queensland; also Christmas Island and Cocos (Keeling) Islands in the eastern Indian Ocean. Elsewhere the species occurs in the tropical, Indo-west-central Pacific.


Detrivore - although this territorial damsel fish actively cultivates and defends a thick turf on the branches of acropora corals, studies have shown that the gut contents are dominated by detritus material. Small amounts of algae and invertebrates such as polychaetes, crustaceans and foraminiferans are also consumed (Wilson & Bellwood 1997).


A study in Okinawa, Japan, found that Stegastes nigricans weeds out unpalatable and competitively superior late-colonizingalgae to maintain a virtual monocultural crop of the digestible early-colonizing red algae, Womersleyella setacea (Hata & Kato 2002).

Species Citation

Holocentrus nigricans Lacépède, 1802, Histoire Naturelle des Poissons 4: 332, 367.Type locality; unknown:


Bray, D.J. 2018


Australian Faunal Directory

Dusky Gregory, Stegastes nigricans (Lacépède 1802)


Allen, G.R. 1975. Damselfishes of the South Seas. New Jersey : T.F.H. Publications 237 pp. 251 figs.

Allen, G.R. 1991. Damselfishes of the World. Melle, Germany : Mergus Verlag 271 pp.

Allen, G.R. 1993. Fishes of Ashmore Reef and Cartier Island. Records of the Western Australian Museum, Supplement 44: 67-91

Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Perth : Western Australian Museum 292 pp. 106 pls.

Allen, G. R. 2001. Family Pomacentridae. pp. in Carpenter, K.E. & Niem, T.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 6 pp. 3381-4218.

Allen, G.R., Steene, R.C. & Orchard, M. 2007. Fishes of Christmas Island. Christmas Island : Christmas Island Natural History Association 2 edn, 284 pp.

Allen, G.R. & Emery, A.R. 1985. A review of the pomacentrid fishes of the genus Stegastes from the Indo-west Pacific with descriptions of two new species. Indo-Pacific Fishes 3: 1-31 figs 1-5 pls 1-3

Allen, G.R. & Erdmann, M.V. 2012. Reef fishes of the East Indies. Perth : Tropical Reef Research 3 vols, 1260 pp.

Allen, G.R. & Smith-Vaniz, W.F. 1994. Fishes of Cocos (Keeling) Islands. Atoll Research Bulletin 412: 1-21.

Allen, G.R. & Swainston, R. 1988. The Marine Fishes of North-Western Australia. A field guide for anglers and divers. Perth, WA : Western Australian Museum vi 201 pp., 70 pls.

Barneche, D.R., S.R. Floeter, D.M. Ceccarelli, D.M.B. Fresnel, D.F. Dinslaken, H.F.S. Mario & C.E.L. Ferreira. 2009. Feeding macroecology of territorial damselfishes (Perciformes: Pomacentridae). Marine Biology 156: 289-299.

Casey, J.M., Ainsworth, T.D., Choat, J.H. & Connolly, S.R. 2014. Farming behaviour of reef fishes increases the prevalence of coral disease associated microbes and black band disease. Proceedings of the Royal Society B: Biological Sciences 281(1788): 20141032. DOI: 10.1098/rspb.2014.1032 Open access

Cooper, W.J., Smith, L.L. & Westneat, M.W. 2009. Exploring the radiation of a diverse reef fish family: Phylogenetics of the damselfishes (Pomacentridae), with new classifications based on molecular analyses of all genera. Molecular Phylogenetics and Evolution 52: 1-16.

De Vis, C.W. 1885. New fishes in the Queensland Museum. No. 5. Proceedings of the Linnean Society of New South Wales 1 9(4): 869-887. (described as Pomacentrus subniger)

Galetto, M.J. & Bellwood, D.R. 1994. Digestion of algae by Stegastes nigricans and Amphiprion akindynos (Pisces: Pomacentridae), with an evaluation of methods used in digestibility studies. Journal of Fish Biology 44: 415-428. 

Gobler, C.J., D.B. Thibault, T.W. Davis, P.B. Curran, B.J. Peterson & L.B. Liddle (2006). Algal assemblages associated with Stegastes sp. territories on Indo-Pacific coral reefs: Characterization of diversity and controls on growth. Journal of Experimental Marine Biology and Ecology 336: 135-145. 

Hata, H. & M. Kato (2002). Weeding by the herbivorous damselfish Stegastes nigricans in nearly monocultural algae farms. Marine Ecology Progress Series 237: 227-231. 

Hata, H. & M. Kato (2004). Monoculture and mixed-species algal farms on a coral reef are maintained through intensive and extensive management by damselfishes. Journal of Experimental Marine Biology and Ecology 313: 285-296. 

Hata, H. & M. Kato (2006). A novel obligate cultivation mutualism between damselfish and Polysiphonia algae. Biology Letters 2: 593-596.

Hobbs, J-P.A., Newman, S.J., Mitsopoulos, G.E.A., Travers, M.J., Skepper, C.L., Gilligan, J.J., Allen, G.R., Choat, H.J. & Ayling, A.M. 2014. Checklist and new records of Christmas Island fishes: the influence of isolation, biogeography and habitat availability on species abundance and community composition. Raffles Bulletin of Zoology Supplement 30: 184–202 

Hobbs, J-P.A., Newman, S .J., Mitsopoulos, G.E.A., Travers, M.J., Skepper, C.L., Gilligan, J.J., Allen, G.R., Choat, H.J. & Ayling, A.M. 2014. Fishes of the Cocos (Keeling) Islands: new records, community composition and biogeographic significance. Raffles Bulletin of Zoology Supplement 30: 203–219

Hoey, A.S. & D.R. Bellwood (2010). Damselfish territories as a refuge for macroalgae on coral reefs. Coral Reefs 29: 107-118. 

Hutchins, B. 2004. Fishes of the Dampier Archipelago, Western Australia. Records of the Western Australian Museum, Supplement 66: 343–398

Hutchins, J.B. 1994. A survey of the nearshore reef fish fauna of Western Australia's west and south coasts — The Leeuwin Province. Records of the Western Australian Museum, Supplement46: 1-66 figs 1-6

Hutchins, J.B. 2001. Biodiversity of shallow reef fish assemblages in Western Australia using a rapid censusing technique. Records of the Western Australian Museum 20: 247-270.

Jan, R.Q., C.T. Ho & F.K. Shiah (2003). Determinants of territory size of the Dusky Gregory. Journal of Fish Biology 63: 1589-1597. 

Jones, G.P., L. Santana, L.J. McCook & M.I. McCormick (2006). Resource use and impact of three herbivorous damselfishes on coral reef communities. Marine Ecology Progress Series 328: 215-224.

Karino, K. & T. Kuwamura. (1997). Plasticity in spawning visits of female damselfish, Stegastes nigricans: effect of distance to mates. Behavioural Ecology and Sociobiology 41: 55-59. 

Karino, K. & A. Nakazono. 1993. Reproductive behavior of the territorial herbivore Stegastes nigricans (Pisces: Pomacentridae) in relation to colony formation. Journal of Ethology 11(2): 99-110.

Lacépède, B.G. 1802. Histoire Naturelle des Poissons. Paris : chez Plassan Vol. 4 728 pp. 16 pls.

Letourneur, Y. (2000). Spatial and temporal variability in territoriality of a tropical benthic damselfish on a coral reef (Réunion Island). Environmental Biology of Fishes 57: 377-391. 

Letourneur Y, Galzin R, Harmelin-Vivien M (1997) Temporal variations in the diet of the damselfish Stegastes nigricans (Lacepède) on a Réunion fringing reef. J Exp Mar Biol Ecol 217: 1–18.

Lo-Yat, A., M. Meekan, N. Munksgaard, D. Parry, S. Planes, M. Wolter & J. Carleton. 2005. Small-scale spatial variation in the elemental composition of otoliths of Stegastes nigricans (Pomacentridae) in French Polynesia. Coral Reefs 24(4): 646-653.

Lobel, P.S. 1980. Herbivory by damselfishes and their role in coral reef community ecology. Bulletin of Marine Science 30: 273-289.

Randall, J.E. 2005. Reef and shore fishes of the South Pacific. New Caledonia to Tahiti and the Pitcairn Islands. Honolulu : University of Hawaii Press 707 pp.

Randall, J.E., Allen, G.R. & Steene, R. 1990. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 507 pp. figs.

Randall, J.E., Allen, G.R. & Steene, R. 1997. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 557 pp. figs.

Sau-Fung Lee, J. & G.W. Barlow (2001). Recruiting juvenile damselfish: the process of recruiting into adult colonies in the damselfish Stegastes nigricans. Acta Ethol 4: 23-29.

Thresher, R.E., P.L. Colin & L.J. Bell. 1989. Planktonic duration, distribution and population structure of western and central Pacific damselfishes (Pomacentridae). Copeia 1989(2): 420-434.

Vullioud, P., R. Bshary & A.F.H. Ros (2013). Intra- and interspecific aggression do not modulate androgen levels in dusky gregories, yet male aggression is reduced by an androgen blocker. Hormones and Behavior 64: 430-438.

Wilson, S. & D.R. Bellwood. 1997. Cryptic dietary components of territorial damselfishes (Pomacentridae, Labroidei). Marine Ecology Progress Series 153: 299-310.

Woodland, D.J. & Slack-Smith, R.J. 1963. Fishes of Heron Island, Capricorn Group, Great Barrier Reef. University of Queensland Papers, Department of Zoology 2(2): 15-69, figs 1-2

Quick Facts

CAAB Code:37372135

Depth:1-12 m

Habitat:Reef associated

Max Size:14 cm TL

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Species Maps

CAAB distribution map